1. Field of the Invention
The present invention relates to a dryer, and more particularly to a dryer having a function for detecting temperature.
2. Description of the Prior Art
Among the general household-consumed electricity, the consumed electricity of a dryer is only less than the consumed electricity of an air conditioning system, and the consumed electricity of the dryer is 2-4 times of that of a washing machine or double of that of an energy-saving refrigerator. Thus, reducing the consumed electricity of the dryer is a positive demand for saving household-consumed electricity. However, as to the traditional dryer, a drying time is mostly determined by the user according to own experience. If the drying time is up and the clothing is still not dried, then the user has to set the drying time again to have the clothing dried. It may be understood that the user will usually set a longer drying time to make sure that the clothing can be dried completely. As a result, the clothing may be dried excessively and energy may be wasted.
A traditional dryer has a resistive humidity sensor disposed within the cylinder. When the clothing is contacted with the resistive humidity sensor, the resistive humidity sensor can sense the humidity of the clothing, such that the controller can determine if the drying schedule has to be ended. However, the dryer adopting the resistive humidity sensor has the following shortcomings: (1) The resistive humidity sensor is apt to be polluted by the cotton, so that the resistive humidity sensor cannot be contact with the clothing completely. Thus, a wrong judgment that the clothing has been dried happens, and a false signal is output. As a result, the user needs to restart the drying schedule, and the extra energy consumption happens. (2) In order to avoid a false signal to be produced, the user often needs to clean the resistive humidity sensor, which causes inconvenience in use. (3) When the amount of the clothing is less, the clothing may not be contact with the resistive humidity sensor or be poor contact with the resistive humidity sensor, so that a false signal is output. (4) When the clothing of different properties (such as cotton/chemical fiber, small/large clothing or thick/thin clothing) is mixed and dried, the resistive humidity sensor cannot distinguish accurately whether all the clothing within the cylinder has been dried completely.
If it cannot be determined correctly that all the clothing has been dried completely, the user may abandon the automatic drying schedule and operate manually, which may consume more electricity. The above-mentioned shortcomings may not be overcome even by disposing a plurality of resistive humidity sensors. For this reason, the most important goal for now is to determine correctly that the clothing has been dried completely.